Section 13 Rent Increases: How to Serve Notice Properly

Section 13 rent increases are the formal, legal way to raise rent on a periodic tenancy in Middlesbrough. Get the process right and you protect your income. Get it wrong and the notice is invalid — leaving you with no recourse and a frustrated relationship with your tenant. This guide shows you how to serve notice properly, what the timing rules are, and what happens if your tenant challenges the increase.

When Section 13 Applies

Section 13 of the Housing Act 1988 is your statutory mechanism for increasing rent on assured and assured shorthold tenancies — but only in specific circumstances.

Most importantly: Section 13 applies to periodic tenancies only. Once your tenant's fixed term has ended and they've moved into a periodic arrangement (rolling month-to-month, typically), you can use Section 13. If they're still in the fixed term, you cannot. That distinction alone is why many landlords get stuck.

If your tenancy agreement includes a rent review clause — and many modern agreements do — follow that clause instead. It will specify when and how the rent increases. That takes precedence. Check your agreement first before assuming you need Section 13.

If there's no rent review clause and the tenancy is periodic, Section 13 is your pathway. It's also your only pathway if you want to serve a formal notice; the alternative is negotiating directly with the tenant, which we'll touch on later.

Timing: The Non-Negotiable Rules

Section 13 timing is rigid because it protects tenants from constant rent-chasing. These are the three rules that matter.

One increase per twelve months. You can only increase rent once in any rolling twelve-month period. The clock resets from the date of the last increase (or the start of the tenancy if this is the first). Serve a Section 13 notice too soon and it's invalid. Some landlords don't realise this and serve overlapping notices — both get rejected.

One month's notice for monthly rent periods. If your tenant pays rent monthly, you must give at least one month's notice before the increase takes effect. That notice period must end on the first day of a new rental period. So if rent is due on the 1st and you want the increase to start from 1 March, your notice must arrive by 1 February at the latest.

Specify the effective date clearly. The notice must state the exact date the new rent takes effect. This must be the first day of a rental period. Vagueness or dates mid-period invalidate the notice.

Example: Your TS5 tenant pays £850 monthly on the 1st. Last increase was 1 March 2025. You want to increase to £900 from 1 March 2026. You serve the notice by 1 February 2026. That works. You serve it on 5 February. That doesn't — you've missed the one-month window.

The Form: Get the Version Right

Section 13 notices must use the prescribed form. For assured shorthold tenancies, this is Form 4 (the statutory prescribed form under the Housing (Prescribed Forms) Regulations 1997, as amended).

Using an incorrect form, an outdated version, or a home-made template invalidates the entire notice. The tenant can ignore it. The tribunal won't recognise it. All the effort disappears.

The form is available free on gov.uk. Download the current version every time you need one — do not use a form you found two years ago. Forms get updated, and using an old version is a common reason Section 13 notices fail.

The form must include:

Your full name and address
The tenant's full name(s) and the property address
The current rent amount (and the rental period — weekly, monthly, etc.)
The proposed new rent amount
The date the new rent takes effect (first day of a rental period)
A statement explaining the tenant's right to refer to the First-tier Tribunal and the deadline for doing so
Your signature and the date you serve it

Missing any field can render the form invalid. Double-check before serving. If you're unsure, contact us — we review these regularly and it takes five minutes.

Setting the Rent: What "Market Rate" Actually Means

The law doesn't say you can increase rent by any amount you like. If the tenant disputes the increase, the First-tier Tribunal (Property Chamber) will review it and set what they judge to be the "market rent" for the property. That might be your proposed figure, lower, or (rarely) higher. Either way, it's binding.

This is why setting a reasonable, evidenced increase matters. An increase that's 15% above comparable properties in your postcode is asking for a tribunal referral. One that's in line with local market movement usually isn't challenged.

Research comparable properties in your area before proposing an increase. Rightmove, Zoopla, SpareRoom, and local estate agents all show current asking rents in TS1, TS3, TS5, and TS7. Look at properties similar to yours — same size, condition, location — and see what they're achieving. That's your market-rate anchor.

Also consider: how long has it been since the last increase? If you haven't raised rent in three years, a single larger increase is often justified. If you increased last year, a modest bump is more defensible.

Many landlords worry they'll upset the tenant. A well-timed, modest, explained increase is less likely to trigger a challenge than an aggressive one served with no warning.

Serving the Notice: Evidence Matters

How you deliver the notice matters. The law allows:

Hand delivery to the tenant (get a signature or receipt)
First-class post to the property (use recorded delivery so you have proof)
Email or other electronic means (only if the tenancy agreement explicitly allows it)

Keep proof of service. This is non-negotiable. If the tenant later claims they never received it, you need evidence. A signed hand-delivery note, a recorded-delivery receipt, or an email read-receipt all work. WhatsApp, an unmarked envelope, or "I left it under the door" do not.

Once served correctly, the notice is binding. The clock starts ticking toward the effective date.

What Happens If the Tenant Challenges

A challenge to a Section 13 increase goes to the First-tier Tribunal (Property Chamber), and it only happens if the tenant refers it before the increase date arrives.

When a referral is made, the tribunal will:

Review the market rent for comparable properties
Determine what they judge to be the "market rent" for your property
Set that as the new rent (or confirm your proposed rent if they agree it's market)

The tribunal's decision is binding. You cannot appeal it on grounds of fairness; you can only appeal on points of law (e.g., if the tribunal made a procedural error).

In practice, most tenants don't refer increases to the tribunal. If the increase is reasonable and you've communicated it clearly, the risk is low. A 4–6% increase in line with inflation and local market movement is rarely challenged. A 15% jump will be.

If the tenant does refer it and the tribunal sets the rent lower than you proposed, that's the rent that applies going forward. It's not a "try again next year" — it's the binding determination.

Frequently Asked Questions

Can I use Section 13 during the fixed term?

No. Section 13 only applies to periodic tenancies. Once the fixed term ends and the tenancy becomes periodic, you can use it. During the fixed term, you need the tenant's agreement to increase rent, or you can let the agreement expire and offer a new fixed term at a higher rent.

How do I know if my form is up to date?

Download it from gov.uk each time you need one. Forms are updated periodically, and using an old version can invalidate the notice. If you served a notice two years ago, do not use that form again.

Can I increase rent twice in one year if the tenant agrees?

Yes. If you and the tenant agree in writing to increase rent outside the Section 13 mechanism (i.e., a mutual agreement, not a formal notice), you can do this as often as you both agree. Section 13 has the once-per-twelve-months rule; mutual agreement doesn't. However, always document the agreement in writing and ensure it's clear and signed by both parties.

What if I serve the notice but the date I specify has already passed?

The notice is invalid. The effective date must be in the future when the notice is served, and it must be the first day of a rental period. Re-serve with a correct date.

What counts as "one month's notice" for a monthly tenancy?

It's calendar months, and the notice period ends on the rental period start date (usually the 1st). If you serve on 15 January for a 1 February effective date, that's only two weeks — invalid. Serve by 1 January for a 1 February effective date.

Can the tenant refuse to pay the new rent if they disagree with it but haven't referred it to the tribunal?

Not unless they refer the matter to the tribunal before the effective date. Once the effective date arrives and the notice was properly served, they must pay the new rent or be in breach of tenancy. If they do refer it, they can pay the old rent into the tribunal's trust account until the tribunal decides.

What's the difference between Section 13 and Section 21?

Section 13 is for increasing rent on a periodic tenancy. Section 21 was the old "no-fault" eviction route — it was abolished in October 2024. For more on modern eviction rules, see our guide to Section 21 and Section 8 notices.

Do I need a solicitor to serve Section 13?

No, but you need to get it right. The form is free, the process is straightforward, and thousands of landlords serve Section 13 notices without legal advice. If you're uncertain about anything — timing, form version, comparable rents — get it checked before serving. The cost of a quick review is nothing compared to the cost of serving an invalid notice and getting stuck in an argument with the tenant.

Alternatives: Negotiation and Collaboration

Section 13 is formal, legal, and binding — but it's not the only way to increase rent.

Direct negotiation. Many Middlesbrough landlords prefer to have a conversation with the tenant first. Explain why you're increasing (inflation, maintenance costs, local market movement), propose a figure, listen to concerns, and reach an agreement. If the tenant agrees, document it in writing and both sign it. This approach preserves the relationship and often results in a committed, longer-term tenant.

New fixed-term tenancy. Rather than serving a Section 13 notice on a periodic tenancy, offer a new fixed-term tenancy at the increased rent. This gives both of you certainty: the tenant gets security of tenure, and you get the higher rent locked in for the term.

Rent review clause in the agreement. If you're drafting a new tenancy agreement, include a rent review clause that specifies when and how rent increases happen each year. This makes future increases predictable and avoids the need for formal Section 13 notices.

The advantage of these approaches is they're collaborative. The downside is they rely on tenant agreement. Section 13 is your tool when agreement isn't forthcoming — or when you simply want to follow a formal, documented process.

The Renters Reform Act: What's Changing

The Renters Reform Act is reshaping how Section 13 works. Rent increase frequency, notice periods, and tribunal powers may all shift. For the latest on what's changing in 2026 for Middlesbrough landlords, check our dedicated guide. If you're planning a rent increase now, confirm you're following current rules before serving notice.

Staying on Top of Compliance

Rent increases are one piece of a larger compliance picture. Tenancy deposits, gas safety, EPC standards, and a host of other regulations all have their own rules and timelines. For a full checklist on staying compliant with 2026 letting regulations, see our comprehensive guide.

Key Takeaways

Section 13 notices are the formal, legal way to increase rent on a periodic tenancy. Get the process right and it's straightforward. Get any detail wrong — the form version, the timing, the effective date, the calculation of the twelve-month window — and the notice is invalid and you're back to square one.

Download the current Form 4 from gov.uk. Ensure you're in a periodic tenancy. Check your one-per-twelve-months timing. Set a market-rate increase. Serve correctly and keep proof. That's the process.

If you're managing a portfolio in Middlesbrough, we handle Section 13 increases for our landlords — form selection, timing, tenant communication, and tribunal-referral management if it comes to that. Contact Ascot Knight to discuss how we can take the compliance burden off your hands.